Design and Implementation of Session Border Controller on IMS Access Side

With the development of 3G and 4G,IMS platform has become the core network of rich multimedia communication provided by the mainstream operating at home and abroad,User access side turn to IMS access and mobile Internet,also makes the originally closed user communication system open to Internet and mobile Internet,brings the convenience of communication but also brings the communication security problem. This paper proposes a kind of design method for IP communications application level firewalls of IMS access side namely enterprise session border controller,put forward the system structure of the separated signaling and media,and gives the main realized points of key functions such as the topology hiding,NAT crossing and agent registration. At last,through actual network test shows that this method can effectively isolate the enterprise communication system and ensure the safety of IP communications.